Merge from git-annex.

19 files changed, 597 insertions, 350 deletions

diff --git a/Git/CatFile.hs b/Git/CatFile.hs
index 1769e57..6bea8c0 100644
--- a/Git/CatFile.hs
+++ b/Git/CatFile.hs
@@ -6,6 +6,7 @@
  -}
 
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE BangPatterns #-}
 
 module Git.CatFile (
 	CatFileHandle,
@@ -19,6 +20,9 @@ module Git.CatFile (
 	catObject,
 	catObjectDetails,
 	catObjectMetaData,
+	catObjectStreamLsTree,
+	catObjectStream,
+	catObjectMetaDataStream,
 ) where
 
 import System.IO
@@ -27,12 +31,15 @@ import qualified Data.ByteString.Lazy as L
 import qualified Data.ByteString.Char8 as S8
 import qualified Data.Attoparsec.ByteString as A
 import qualified Data.Attoparsec.ByteString.Char8 as A8
-import qualified Data.Map as M
+import qualified Data.Map.Strict as M
 import Data.String
 import Data.Char
 import Numeric
 import System.Posix.Types
 import Text.Read
+import Control.Concurrent.Async
+import Control.Concurrent.Chan
+import Control.Monad.IO.Class (MonadIO)
 
 import Common
 import Git
@@ -40,9 +47,10 @@ import Git.Sha
 import qualified Git.Ref
 import Git.Command
 import Git.Types
-import Git.FilePath
 import Git.HashObject
+import qualified Git.LsTree as LsTree
 import qualified Utility.CoProcess as CoProcess
+import qualified Git.BuildVersion as BuildVersion
 import Utility.Tuple
 
 data CatFileHandle = CatFileHandle 
@@ -57,7 +65,7 @@ catFileStart = catFileStart' True
 catFileStart' :: Bool -> Repo -> IO CatFileHandle
 catFileStart' restartable repo = CatFileHandle
 	<$> startp "--batch"
-	<*> startp "--batch-check=%(objectname) %(objecttype) %(objectsize)"
+	<*> startp ("--batch-check=" ++ batchFormat)
 	<*> pure repo
   where
 	startp p = gitCoProcessStart restartable
@@ -65,6 +73,9 @@ catFileStart' restartable repo = CatFileHandle
 		, Param p
 		] repo
 
+batchFormat :: String
+batchFormat = "%(objectname) %(objecttype) %(objectsize)"
+
 catFileStop :: CatFileHandle -> IO ()
 catFileStop h = do
 	CoProcess.stop (catFileProcess h)
@@ -72,12 +83,12 @@ catFileStop h = do
 
 {- Reads a file from a specified branch. -}
 catFile :: CatFileHandle -> Branch -> RawFilePath -> IO L.ByteString
-catFile h branch file = catObject h $ Ref $
-	fromRef' branch <> ":" <> toInternalGitPath file
+catFile h branch file = catObject h $
+	Git.Ref.branchFileRef branch file
 
 catFileDetails :: CatFileHandle -> Branch -> RawFilePath -> IO (Maybe (L.ByteString, Sha, ObjectType))
-catFileDetails h branch file = catObjectDetails h $ Ref $
-	fromRef' branch <> ":" <> toInternalGitPath file
+catFileDetails h branch file = catObjectDetails h $ 
+	Git.Ref.branchFileRef branch file
 
 {- Uses a running git cat-file read the content of an object.
  - Objects that do not exist will have "" returned. -}
@@ -88,18 +99,12 @@ catObjectDetails :: CatFileHandle -> Ref -> IO (Maybe (L.ByteString, Sha, Object
 catObjectDetails h object = query (catFileProcess h) object newlinefallback $ \from -> do
 	header <- S8.hGetLine from
 	case parseResp object header of
-		Just (ParsedResp sha objtype size) -> do
-			content <- S.hGet from (fromIntegral size)
-			eatchar '\n' from
-			return $ Just (L.fromChunks [content], sha, objtype)
+		Just r@(ParsedResp sha objtype _size) -> do
+			content <- readObjectContent from r
+			return $ Just (content, sha, objtype)
 		Just DNE -> return Nothing
 		Nothing -> error $ "unknown response from git cat-file " ++ show (header, object)
   where
-	eatchar expected from = do
-		c <- hGetChar from
-		when (c /= expected) $
-			error $ "missing " ++ (show expected) ++ " from git cat-file"
-	
 	-- Slow fallback path for filenames containing newlines.
 	newlinefallback = queryObjectType object (gitRepo h) >>= \case
 		Nothing -> return Nothing
@@ -113,6 +118,18 @@ catObjectDetails h object = query (catFileProcess h) object newlinefallback $ \f
 					(gitRepo h)
 				return (Just (content, sha, objtype))
 
+readObjectContent :: Handle -> ParsedResp -> IO L.ByteString
+readObjectContent h (ParsedResp _ _ size) = do
+	content <- S.hGet h (fromIntegral size)
+	eatchar '\n'
+	return (L.fromChunks [content])
+  where
+	eatchar expected = do
+		c <- hGetChar h
+		when (c /= expected) $
+			error $ "missing " ++ (show expected) ++ " from git cat-file"
+readObjectContent _ DNE = error "internal"
+
 {- Gets the size and type of an object, without reading its content. -}
 catObjectMetaData :: CatFileHandle -> Ref -> IO (Maybe (Sha, FileSize, ObjectType))
 catObjectMetaData h object = query (checkFileProcess h) object newlinefallback $ \from -> do
@@ -180,14 +197,16 @@ querySingle o r repo reader = assertLocal repo $
 			, std_in = Inherit
 			, std_out = CreatePipe
 			}
-		pid <- createProcess p'
-		let h = stdoutHandle pid
-		output <- reader h
-		hClose h
-		ifM (checkSuccessProcess (processHandle pid))
+		withCreateProcess p' go
+  where
+	go _ (Just outh) _ pid = do
+		output <- reader outh
+		hClose outh
+		ifM (checkSuccessProcess pid)
 			( return (Just output)
 			, return Nothing
 			)
+	go _ _ _ _ = error "internal"
 
 querySize :: Ref -> Repo -> IO (Maybe FileSize)
 querySize r repo = maybe Nothing (readMaybe . takeWhile (/= '\n'))
@@ -264,3 +283,123 @@ parseCommit b = Commit
 	sp = fromIntegral (ord ' ')
 	lt = fromIntegral (ord '<')
 	gt = fromIntegral (ord '>')
+
+{- Uses cat-file to stream the contents of the files as efficiently
+ - as possible. This is much faster than querying it repeatedly per file.
+ -}
+catObjectStreamLsTree
+	:: (MonadMask m, MonadIO m)
+	=> [LsTree.TreeItem]
+	-> (LsTree.TreeItem -> Maybe v)
+	-> Repo
+	-> (IO (Maybe (v, Maybe L.ByteString)) -> m a)
+	-> m a
+catObjectStreamLsTree l want repo reader = withCatFileStream False repo $
+	\c hin hout -> bracketIO
+		(async $ feeder c hin)
+		cancel
+		(const (reader (catObjectReader readObjectContent c hout)))
+  where
+	feeder c h = do
+		forM_ l $ \ti -> case want ti of
+			Nothing -> return ()
+			Just v -> do
+				let sha = LsTree.sha ti
+				liftIO $ writeChan c (sha, v)
+				S8.hPutStrLn h (fromRef' sha)
+		hClose h
+
+catObjectStream
+	:: (MonadMask m, MonadIO m)
+	=> Repo
+	-> (
+	    ((v, Ref) -> IO ()) -- ^ call to feed values in
+	    -> IO () -- call once all values are fed in
+	    -> IO (Maybe (v, Maybe L.ByteString)) -- call to read results
+	    -> m a
+	   )
+	-> m a
+catObjectStream repo a = withCatFileStream False repo go
+  where
+	go c hin hout = a
+		(feeder c hin)
+		(hClose hin)
+		(catObjectReader readObjectContent c hout)
+	feeder c h (v, ref) = do
+		liftIO $ writeChan c (ref, v)
+		S8.hPutStrLn h (fromRef' ref)
+
+catObjectMetaDataStream
+	:: (MonadMask m, MonadIO m)
+	=> Repo
+	-> (
+	    ((v, Ref) -> IO ()) -- ^ call to feed values in
+	    -> IO () -- call once all values are fed in
+	    -> IO (Maybe (v, Maybe (Sha, FileSize, ObjectType))) -- call to read results
+	    -> m a
+	   )
+	-> m a
+catObjectMetaDataStream repo a = withCatFileStream True repo go
+  where
+	go c hin hout = a
+		(feeder c hin)
+		(hClose hin)
+		(catObjectReader (\_h r -> pure (conv r)) c hout)
+	
+	feeder c h (v, ref) = do
+		liftIO $ writeChan c (ref, v)
+		S8.hPutStrLn h (fromRef' ref)
+	
+	conv (ParsedResp sha ty sz) = (sha, sz, ty)
+	conv DNE = error "internal"
+
+catObjectReader
+	:: (Handle -> ParsedResp -> IO t)
+	-> Chan (Ref, a)
+	-> Handle
+	-> IO (Maybe (a, Maybe t))
+catObjectReader getv c h = ifM (hIsEOF h)
+	( return Nothing
+	, do
+		(ref, f) <- liftIO $ readChan c
+		resp <- S8.hGetLine h
+		case parseResp ref resp of
+			Just r@(ParsedResp {}) -> do
+				v <- getv h r
+				return (Just (f, Just v))
+			Just DNE -> return (Just (f, Nothing))
+			Nothing -> error $ "unknown response from git cat-file " ++ show resp
+	)
+
+withCatFileStream
+	:: (MonadMask m, MonadIO m)
+	=> Bool
+	-> Repo
+	-> (Chan v -> Handle -> Handle -> m a)
+	-> m a
+withCatFileStream check repo reader = assertLocal repo $
+	bracketIO start stop $ \(c, hin, hout, _) -> reader c hin hout
+  where
+	params = catMaybes
+		[ Just $ Param "cat-file"
+		, Just $ Param ("--batch" ++ (if check then "-check" else "") ++ "=" ++ batchFormat)
+		-- This option makes it faster, but is not present in
+		-- older versions of git.
+		, if BuildVersion.older "2.4.3"
+			then Nothing
+			else Just $ Param "--buffer"
+		]
+
+	start = do
+		let p = gitCreateProcess params repo
+		(Just hin, Just hout, _, pid) <- createProcess p
+			{ std_in = CreatePipe
+			, std_out = CreatePipe
+			}
+		c <- newChan
+		return (c, hin, hout, pid)
+	
+	stop (_, hin, hout, pid) = do
+		hClose hin
+		hClose hout
+		void $ checkSuccessProcess pid
diff --git a/Git/Command.hs b/Git/Command.hs
index 15157a0..fef7eb9 100644
--- a/Git/Command.hs
+++ b/Git/Command.hs
@@ -1,6 +1,6 @@
 {- running git commands
  -
- - Copyright 2010-2013 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -43,15 +43,19 @@ run params repo = assertLocal repo $
 
 {- Runs git and forces it to be quiet, throwing an error if it fails. -}
 runQuiet :: [CommandParam] -> Repo -> IO ()
-runQuiet params repo = withQuietOutput createProcessSuccess $
-	(proc "git" $ toCommand $ gitCommandLine (params) repo)
-		{ env = gitEnv repo }
+runQuiet params repo = withNullHandle $ \nullh ->
+	let p = (proc "git" $ toCommand $ gitCommandLine (params) repo)
+		{ env = gitEnv repo
+		, std_out = UseHandle nullh
+		, std_err = UseHandle nullh
+		}
+	in withCreateProcess p $ \_ _ _ -> forceSuccessProcess p
 
 {- Runs a git command and returns its output, lazily.
  -
  - Also returns an action that should be used when the output is all
  - read, that will wait on the command, and
- - return True if it succeeded. Failure to wait will result in zombies.
+ - return True if it succeeded.
  -}
 pipeReadLazy :: [CommandParam] -> Repo -> IO (L.ByteString, IO Bool)
 pipeReadLazy params repo = assertLocal repo $ do
@@ -70,13 +74,17 @@ pipeReadStrict = pipeReadStrict' S.hGetContents
 
 {- The reader action must be strict. -}
 pipeReadStrict' :: (Handle -> IO a) -> [CommandParam] -> Repo -> IO a
-pipeReadStrict' reader params repo = assertLocal repo $
-	withHandle StdoutHandle (createProcessChecked ignoreFailureProcess) p $ \h -> do
-		output <- reader h
-		hClose h
-		return output
+pipeReadStrict' reader params repo = assertLocal repo $ withCreateProcess p go
   where
-	p  = gitCreateProcess params repo
+	p  = (gitCreateProcess params repo)
+		{ std_out = CreatePipe }
+
+	go _ (Just outh) _ pid = do
+		output <- reader outh
+		hClose outh
+		void $ waitForProcess pid
+		return output
+	go _ _ _ _ = error "internal"
 
 {- Runs a git command, feeding it an input, and returning its output,
  - which is expected to be fairly small, since it's all read into memory
@@ -95,9 +103,16 @@ pipeWriteRead params writer repo = assertLocal repo $
 
 {- Runs a git command, feeding it input on a handle with an action. -}
 pipeWrite :: [CommandParam] -> Repo -> (Handle -> IO ()) -> IO ()
-pipeWrite params repo = assertLocal repo $ 
-	withHandle StdinHandle createProcessSuccess $
-		gitCreateProcess params repo
+pipeWrite params repo feeder = assertLocal repo $
+	let p = (gitCreateProcess params repo)
+		{ std_in = CreatePipe }
+	in withCreateProcess p (go p)
+  where
+	go p (Just hin) _ _ pid = do
+		feeder hin
+		hClose hin
+		forceSuccessProcess p pid
+	go _ _ _ _ _ = error "internal"
 
 {- Reads null terminated output of a git command (as enabled by the -z 
  - parameter), and splits it. -}
@@ -119,16 +134,6 @@ pipeNullSplitStrict params repo = do
 	s <- pipeReadStrict params repo
 	return $ filter (not . S.null) $ S.split 0 s
 
-pipeNullSplitZombie :: [CommandParam] -> Repo -> IO [L.ByteString]
-pipeNullSplitZombie params repo = leaveZombie <$> pipeNullSplit params repo
-
-pipeNullSplitZombie' :: [CommandParam] -> Repo -> IO [S.ByteString]
-pipeNullSplitZombie' params repo = leaveZombie <$> pipeNullSplit' params repo
-
-{- Doesn't run the cleanup action. A zombie results. -}
-leaveZombie :: (a, IO Bool) -> a
-leaveZombie = fst
-
 {- Runs a git command as a coprocess. -}
 gitCoProcessStart :: Bool -> [CommandParam] -> Repo -> IO CoProcess.CoProcessHandle
 gitCoProcessStart restartable params repo = CoProcess.start numrestarts "git"
diff --git a/Git/Config.hs b/Git/Config.hs
index f50d5eb..20ddf79 100644
--- a/Git/Config.hs
+++ b/Git/Config.hs
@@ -58,29 +58,37 @@ read' repo = go repo
 	go Repo { location = Local { gitdir = d } } = git_config d
 	go Repo { location = LocalUnknown d } = git_config d
 	go _ = assertLocal repo $ error "internal"
-	git_config d = withHandle StdoutHandle createProcessSuccess p $
-		hRead repo ConfigNullList
+	git_config d = withCreateProcess p (git_config' p)
 	  where
 		params = ["config", "--null", "--list"]
 		p = (proc "git" params)
 			{ cwd = Just (fromRawFilePath d)
 			, env = gitEnv repo
+			, std_out = CreatePipe 
 			}
+	git_config' p _ (Just hout) _ pid = 
+		forceSuccessProcess p pid
+			`after`
+		hRead repo ConfigNullList hout
+	git_config' _ _ _ _ _ = error "internal"
 
 {- Gets the global git config, returning a dummy Repo containing it. -}
 global :: IO (Maybe Repo)
 global = do
 	home <- myHomeDir
 	ifM (doesFileExist $ home </> ".gitconfig")
-		( do
-			repo <- withHandle StdoutHandle createProcessSuccess p $
-				hRead (Git.Construct.fromUnknown) ConfigNullList
-			return $ Just repo
+		( Just <$> withCreateProcess p go
 		, return Nothing
 		)
   where
 	params = ["config", "--null", "--list", "--global"]
 	p = (proc "git" params)
+		{ std_out = CreatePipe }
+	go _ (Just hout) _ pid = 
+		forceSuccessProcess p pid
+			`after`
+		hRead (Git.Construct.fromUnknown) ConfigNullList hout
+	go _ _ _ _ = error "internal"
 
 {- Reads git config from a handle and populates a repo with it. -}
 hRead :: Repo -> ConfigStyle -> Handle -> IO Repo
@@ -132,9 +140,9 @@ updateLocation' r l = do
 		Nothing -> return l
 		Just (ConfigValue d) -> do
 			{- core.worktree is relative to the gitdir -}
-			top <- absPath $ fromRawFilePath (gitdir l)
-			let p = absPathFrom top (fromRawFilePath d)
-			return $ l { worktree = Just (toRawFilePath p) }
+			top <- absPath (gitdir l)
+			let p = absPathFrom top d
+			return $ l { worktree = Just p }
 		Just NoConfigValue -> return l
 	return $ r { location = l' }
 
@@ -177,6 +185,10 @@ isTrueFalse' (ConfigValue s)
 	| s' == "0" = Just False
 	| s' == "" = Just False
 
+	-- Git treats any number other than 0 as true,
+	-- including negative numbers.
+	| S8.all (\c -> isDigit c || c == '-') s' = Just True
+
 	| otherwise = Nothing
   where
 	s' = S8.map toLower s
@@ -198,22 +210,30 @@ coreBare = "core.bare"
 
 {- Runs a command to get the configuration of a repo,
  - and returns a repo populated with the configuration, as well as the raw
- - output and any standard output of the command. -}
-fromPipe :: Repo -> String -> [CommandParam] -> ConfigStyle -> IO (Either SomeException (Repo, S.ByteString, S.ByteString))
-fromPipe r cmd params st = try $
-	withOEHandles createProcessSuccess p $ \(hout, herr) -> do
-		geterr <- async $ S.hGetContents herr
-		getval <- async $ S.hGetContents hout
-		val <- wait getval
-		err <- wait geterr
-		r' <- store val st r
-		return (r', val, err)
+ - output and the standard error of the command. -}
+fromPipe :: Repo -> String -> [CommandParam] -> ConfigStyle -> IO (Either SomeException (Repo, S.ByteString, String))
+fromPipe r cmd params st = tryNonAsync $ withCreateProcess p go
   where
-	p = proc cmd $ toCommand params
+	p = (proc cmd $ toCommand params)
+		{ std_out = CreatePipe
+		, std_err = CreatePipe
+		}
+	go _ (Just hout) (Just herr) pid =
+		withAsync (getstderr pid herr []) $ \errreader -> do
+			val <- S.hGetContents hout
+			err <- wait errreader
+			forceSuccessProcess p pid
+			r' <- store val st r
+			return (r', val, err)
+	go _ _ _ _ = error "internal"
+
+	getstderr pid herr c = hGetLineUntilExitOrEOF pid herr >>= \case
+		Just l -> getstderr pid herr (l:c)
+		Nothing -> return (unlines (reverse c))
 
 {- Reads git config from a specified file and returns the repo populated
  - with the configuration. -}
-fromFile :: Repo -> FilePath -> IO (Either SomeException (Repo, S.ByteString, S.ByteString))
+fromFile :: Repo -> FilePath -> IO (Either SomeException (Repo, S.ByteString, String))
 fromFile r f = fromPipe r "git"
 	[ Param "config"
 	, Param "--file"
diff --git a/Git/Construct.hs b/Git/Construct.hs
index 5b656eb..8b63ac4 100644
--- a/Git/Construct.hs
+++ b/Git/Construct.hs
@@ -1,10 +1,11 @@
 {- Construction of Git Repo objects
  -
- - Copyright 2010-2012 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE CPP #-}
 
 module Git.Construct (
@@ -21,6 +22,7 @@ module Git.Construct (
 	repoAbsPath,
 	checkForRepo,
 	newFrom,
+	adjustGitDirFile,
 ) where
 
 #ifndef mingw32_HOST_OS
@@ -37,6 +39,9 @@ import Git.FilePath
 import qualified Git.Url as Url
 import Utility.UserInfo
 
+import qualified Data.ByteString as B
+import qualified System.FilePath.ByteString as P
+
 {- Finds the git repository used for the cwd, which may be in a parent
  - directory. -}
 fromCwd :: IO (Maybe Repo)
@@ -45,40 +50,40 @@ fromCwd = getCurrentDirectory >>= seekUp
 	seekUp dir = do
 		r <- checkForRepo dir
 		case r of
-			Nothing -> case upFrom dir of
+			Nothing -> case upFrom (toRawFilePath dir) of
 				Nothing -> return Nothing
-				Just d -> seekUp d
+				Just d -> seekUp (fromRawFilePath d)
 			Just loc -> pure $ Just $ newFrom loc
 
 {- Local Repo constructor, accepts a relative or absolute path. -}
-fromPath :: FilePath -> IO Repo
+fromPath :: RawFilePath -> IO Repo
 fromPath dir = fromAbsPath =<< absPath dir
 
 {- Local Repo constructor, requires an absolute path to the repo be
  - specified. -}
-fromAbsPath :: FilePath -> IO Repo
+fromAbsPath :: RawFilePath -> IO Repo
 fromAbsPath dir
-	| absoluteGitPath (encodeBS dir) = hunt
+	| absoluteGitPath dir = hunt
 	| otherwise =
-		error $ "internal error, " ++ dir ++ " is not absolute"
+		error $ "internal error, " ++ show dir ++ " is not absolute"
   where
-	ret = pure . newFrom . LocalUnknown . toRawFilePath
-	canondir = dropTrailingPathSeparator dir
+	ret = pure . newFrom . LocalUnknown
+	canondir = P.dropTrailingPathSeparator dir
 	{- When dir == "foo/.git", git looks for "foo/.git/.git",
 	 - and failing that, uses "foo" as the repository. -}
 	hunt
-		| (pathSeparator:".git") `isSuffixOf` canondir =
-			ifM (doesDirectoryExist $ dir </> ".git")
+		| (P.pathSeparator `B.cons` ".git") `B.isSuffixOf` canondir =
+			ifM (doesDirectoryExist $ fromRawFilePath dir </> ".git")
 				( ret dir
-				, ret (takeDirectory canondir)
+				, ret (P.takeDirectory canondir)
 				)
-		| otherwise = ifM (doesDirectoryExist dir)
-			( ret dir
+		| otherwise = ifM (doesDirectoryExist (fromRawFilePath dir))
+			( checkGitDirFile dir >>= maybe (ret dir) (pure . newFrom)
 			-- git falls back to dir.git when dir doesn't
 			-- exist, as long as dir didn't end with a
 			-- path separator
 			, if dir == canondir
-				then ret (dir ++ ".git")
+				then ret (dir <> ".git")
 				else ret dir
 			)
 
@@ -94,7 +99,8 @@ fromUrl url
 
 fromUrlStrict :: String -> IO Repo
 fromUrlStrict url
-	| "file://" `isPrefixOf` url = fromAbsPath $ unEscapeString $ uriPath u
+	| "file://" `isPrefixOf` url = fromAbsPath $ toRawFilePath $
+		unEscapeString $ uriPath u
 	| otherwise = pure $ newFrom $ Url u
   where
 	u = fromMaybe bad $ parseURI url
@@ -128,7 +134,8 @@ fromRemotes repo = mapM construct remotepairs
 	filterconfig f = filter f $ M.toList $ config repo
 	filterkeys f = filterconfig (\(k,_) -> f k)
 	remotepairs = filterkeys isRemoteKey
-	construct (k,v) = remoteNamedFromKey k (fromRemoteLocation (fromConfigValue v) repo)
+	construct (k,v) = remoteNamedFromKey k $
+		fromRemoteLocation (fromConfigValue v) repo
 
 {- Sets the name of a remote when constructing the Repo to represent it. -}
 remoteNamed :: String -> IO Repo -> IO Repo
@@ -154,18 +161,18 @@ fromRemoteLocation s repo = gen $ parseRemoteLocation s repo
 fromRemotePath :: FilePath -> Repo -> IO Repo
 fromRemotePath dir repo = do
 	dir' <- expandTilde dir
-	fromPath $ fromRawFilePath (repoPath repo) </> dir'
+	fromPath $ repoPath repo P.</> toRawFilePath dir'
 
 {- Git remotes can have a directory that is specified relative
  - to the user's home directory, or that contains tilde expansions.
  - This converts such a directory to an absolute path.
  - Note that it has to run on the system where the remote is.
  -}
-repoAbsPath :: FilePath -> IO FilePath
+repoAbsPath :: RawFilePath -> IO RawFilePath
 repoAbsPath d = do
-	d' <- expandTilde d
+	d' <- expandTilde (fromRawFilePath d)
 	h <- myHomeDir
-	return $ h </> d'
+	return $ toRawFilePath $ h </> d'
 
 expandTilde :: FilePath -> IO FilePath
 #ifdef mingw32_HOST_OS
@@ -198,7 +205,7 @@ expandTilde = expandt True
 checkForRepo :: FilePath -> IO (Maybe RepoLocation)
 checkForRepo dir = 
 	check isRepo $
-		check gitDirFile $
+		check (checkGitDirFile (toRawFilePath dir)) $
 			check isBareRepo $
 				return Nothing
   where
@@ -217,22 +224,40 @@ checkForRepo dir =
 		gitSignature (".git" </> "gitdir")
 	isBareRepo = checkdir $ gitSignature "config"
 		<&&> doesDirectoryExist (dir </> "objects")
-	gitDirFile = do
-		-- git-submodule, git-worktree, and --separate-git-dir
-		-- make .git be a file pointing to the real git directory.
-		c <- firstLine <$>
-			catchDefaultIO "" (readFile $ dir </> ".git")
-		return $ if gitdirprefix `isPrefixOf` c
-			then Just $ Local 
-				{ gitdir = toRawFilePath $ absPathFrom dir $
-					drop (length gitdirprefix) c
-				, worktree = Just (toRawFilePath dir)
-				}
-			else Nothing
-	  where
-		gitdirprefix = "gitdir: "
 	gitSignature file = doesFileExist $ dir </> file
 
+-- Check for a .git file.
+checkGitDirFile :: RawFilePath -> IO (Maybe RepoLocation)
+checkGitDirFile dir = adjustGitDirFile' $ Local 
+	{ gitdir = dir P.</> ".git"
+	, worktree = Just dir
+	}
+
+-- git-submodule, git-worktree, and --separate-git-dir
+-- make .git be a file pointing to the real git directory.
+-- Detect that, and return a RepoLocation with gitdir pointing 
+-- to the real git directory.
+adjustGitDirFile :: RepoLocation -> IO RepoLocation
+adjustGitDirFile loc = fromMaybe loc <$> adjustGitDirFile' loc
+
+adjustGitDirFile' :: RepoLocation -> IO (Maybe RepoLocation)
+adjustGitDirFile' loc = do
+	let gd = gitdir loc
+	c <- firstLine <$> catchDefaultIO "" (readFile (fromRawFilePath gd))
+	if gitdirprefix `isPrefixOf` c
+		then do
+			top <- fromRawFilePath . P.takeDirectory <$> absPath gd
+			return $ Just $ loc
+				{ gitdir = absPathFrom 
+					(toRawFilePath top)
+					(toRawFilePath 
+						(drop (length gitdirprefix) c))
+				}
+		else return Nothing
+ where
+	gitdirprefix = "gitdir: "
+
+
 newFrom :: RepoLocation -> Repo
 newFrom l = Repo
 	{ location = l
diff --git a/Git/CurrentRepo.hs b/Git/CurrentRepo.hs
index 054a81e..25bdc5c 100644
--- a/Git/CurrentRepo.hs
+++ b/Git/CurrentRepo.hs
@@ -1,10 +1,12 @@
 {- The current git repository.
  -
- - Copyright 2012 Joey Hess <id@joeyh.name>
+ - Copyright 2012-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
+{-# LANGUAGE OverloadedStrings #-}
+
 module Git.CurrentRepo where
 
 import Common
@@ -13,6 +15,10 @@ import Git.Construct
 import qualified Git.Config
 import Utility.Env
 import Utility.Env.Set
+import qualified Utility.RawFilePath as R
+
+import qualified Data.ByteString as B
+import qualified System.FilePath.ByteString as P
 
 {- Gets the current git repository.
  -
@@ -37,14 +43,14 @@ get = do
 	gd <- getpathenv "GIT_DIR"
 	r <- configure gd =<< fromCwd
 	prefix <- getpathenv "GIT_PREFIX"
-	wt <- maybe (fromRawFilePath <$> worktree (location r)) Just
+	wt <- maybe (worktree (location r)) Just
 		<$> getpathenvprefix "GIT_WORK_TREE" prefix
 	case wt of
 		Nothing -> return r
 		Just d -> do
-			curr <- getCurrentDirectory
+			curr <- R.getCurrentDirectory
 			unless (d `dirContains` curr) $
-				setCurrentDirectory d
+				setCurrentDirectory (fromRawFilePath d)
 			return $ addworktree wt r
   where
 	getpathenv s = do
@@ -52,34 +58,35 @@ get = do
 		case v of
 			Just d -> do
 				unsetEnv s
-				return (Just d)
+				return (Just (toRawFilePath d))
 			Nothing -> return Nothing
 	
-	getpathenvprefix s (Just prefix) | not (null prefix) =
+	getpathenvprefix s (Just prefix) | not (B.null prefix) =
 		getpathenv s >>= \case
 			Nothing -> return Nothing
 			Just d
 				| d == "." -> return (Just d)
-				| otherwise -> Just <$> absPath (prefix </> d)
+				| otherwise -> Just 
+					<$> absPath (prefix P.</> d)
 	getpathenvprefix s _ = getpathenv s
 
 	configure Nothing (Just r) = Git.Config.read r
 	configure (Just d) _ = do
 		absd <- absPath d
-		curr <- getCurrentDirectory
-		r <- Git.Config.read $ newFrom $
-			Local
-				{ gitdir = toRawFilePath absd
-				, worktree = Just (toRawFilePath curr)
-				}
+		curr <- R.getCurrentDirectory
+		loc <- adjustGitDirFile $ Local
+			{ gitdir = absd
+			, worktree = Just curr
+			}
+		r <- Git.Config.read $ newFrom loc
 		return $ if Git.Config.isBare r
 			then r { location = (location r) { worktree = Nothing } }
 			else r
-
 	configure Nothing Nothing = giveup "Not in a git repository."
 
 	addworktree w r = changelocation r $ Local
 		{ gitdir = gitdir (location r)
-		, worktree = fmap toRawFilePath w
+		, worktree = w
 		}
+	
 	changelocation r l = r { location = l }
diff --git a/Git/Destroyer.hs b/Git/Destroyer.hs
index 3dc8529..4d84eec 100644
--- a/Git/Destroyer.hs
+++ b/Git/Destroyer.hs
@@ -95,12 +95,12 @@ applyDamage ds r = do
 		case d of
 			Empty s -> withfile s $ \f ->
 				withSaneMode f $ do
-					nukeFile f
+					removeWhenExistsWith removeLink f
 					writeFile f ""
 			Reverse s -> withfile s $ \f ->
 				withSaneMode f $
 					B.writeFile f =<< B.reverse <$> B.readFile f
-			Delete s -> withfile s $ nukeFile
+			Delete s -> withfile s $ removeWhenExistsWith removeLink
 			AppendGarbage s garbage ->
 				withfile s $ \f ->
 					withSaneMode f $
@@ -145,4 +145,5 @@ applyDamage ds r = do
 		]
 
 withSaneMode :: FilePath -> IO () -> IO ()
-withSaneMode f = withModifiedFileMode f (addModes [ownerWriteMode, ownerReadMode])
+withSaneMode f = withModifiedFileMode (toRawFilePath f)
+	(addModes [ownerWriteMode, ownerReadMode])
diff --git a/Git/FilePath.hs b/Git/FilePath.hs
index d31b421..feed8f6 100644
--- a/Git/FilePath.hs
+++ b/Git/FilePath.hs
@@ -58,8 +58,7 @@ fromTopFilePath p repo = P.combine (repoPath repo) (getTopFilePath p)
 
 {- The input FilePath can be absolute, or relative to the CWD. -}
 toTopFilePath :: RawFilePath -> Git.Repo -> IO TopFilePath
-toTopFilePath file repo = TopFilePath . toRawFilePath
-	<$> relPathDirToFile (fromRawFilePath (repoPath repo)) (fromRawFilePath file)
+toTopFilePath file repo = TopFilePath <$> relPathDirToFile (repoPath repo) file
 
 {- The input RawFilePath must already be relative to the top of the git
  - repository -}
diff --git a/Git/Filename.hs b/Git/Filename.hs
index 010e5ba..2fa4c59 100644
--- a/Git/Filename.hs
+++ b/Git/Filename.hs
@@ -10,6 +10,7 @@ module Git.Filename where
 
 import Common
 import Utility.Format (decode_c, encode_c)
+import Utility.QuickCheck
 
 import Data.Char
 import Data.Word
@@ -35,21 +36,14 @@ decode b = case S.uncons b of
 encode :: RawFilePath -> S.ByteString
 encode s = encodeBS $ "\"" ++ encode_c (decodeBS s) ++ "\""
 
-prop_encode_decode_roundtrip :: FilePath -> Bool
-prop_encode_decode_roundtrip s = s' ==
-	fromRawFilePath (decode (encode (toRawFilePath s')))
+-- Encoding and then decoding roundtrips only when the string does not
+-- contain high unicode, because eg,  both "\12345" and "\227\128\185"
+-- are encoded to "\343\200\271".
+--
+-- That is not a real-world problem, and using TestableFilePath
+-- limits what's tested to ascii, so avoids running into it.
+prop_encode_decode_roundtrip :: TestableFilePath -> Bool
+prop_encode_decode_roundtrip ts = 
+	s == fromRawFilePath (decode (encode (toRawFilePath s)))
   where
-	s' = nonul (nohigh s)
-	-- Encoding and then decoding roundtrips only when
-	-- the string does not contain high unicode, because eg, 
-	-- both "\12345" and "\227\128\185" are encoded to
-	-- "\343\200\271".
-	--
-	-- This property papers over the problem, by only
-	-- testing ascii
-	nohigh = filter isAscii
-	-- A String can contain a NUL, but toRawFilePath
-	-- truncates on the NUL, which is generally fine
-	-- because unix filenames cannot contain NUL.
-	-- So the encoding only roundtrips when there is no nul.
-	nonul = filter (/= '\NUL')
+	s = fromTestableFilePath ts
diff --git a/Git/Fsck.hs b/Git/Fsck.hs
index 69a9e9f..7440b92 100644
--- a/Git/Fsck.hs
+++ b/Git/Fsck.hs
@@ -77,27 +77,31 @@ findBroken batchmode r = do
 		then toBatchCommand (command, params)
 		else return (command, params)
 	
-	p@(_, _, _, pid) <- createProcess $
-		(proc command' (toCommand params'))
-			{ std_out = CreatePipe
-			, std_err = CreatePipe
-			}
-	(o1, o2) <- concurrently
-		(parseFsckOutput maxobjs r (stdoutHandle p))
-		(parseFsckOutput maxobjs r (stderrHandle p))
-	fsckok <- checkSuccessProcess pid
-	case mappend o1 o2 of
-		FsckOutput badobjs truncated
-			| S.null badobjs && not fsckok -> return FsckFailed
-			| otherwise -> return $ FsckFoundMissing badobjs truncated
-		NoFsckOutput
-			| not fsckok -> return FsckFailed
-			| otherwise -> return noproblem
-		-- If all fsck output was duplicateEntries warnings,
-		-- the repository is not broken, it just has some unusual
-		-- tree objects in it. So ignore nonzero exit status.
-		AllDuplicateEntriesWarning -> return noproblem
+	let p = (proc command' (toCommand params'))
+		{ std_out = CreatePipe
+		, std_err = CreatePipe
+		}
+	withCreateProcess p go
   where
+	go _ (Just outh) (Just errh) pid = do
+		(o1, o2) <- concurrently
+			(parseFsckOutput maxobjs r outh pid)
+			(parseFsckOutput maxobjs r errh pid)
+		fsckok <- checkSuccessProcess pid
+		case mappend o1 o2 of
+			FsckOutput badobjs truncated
+				| S.null badobjs && not fsckok -> return FsckFailed
+				| otherwise -> return $ FsckFoundMissing badobjs truncated
+			NoFsckOutput
+				| not fsckok -> return FsckFailed
+				| otherwise -> return noproblem
+			-- If all fsck output was duplicateEntries warnings,
+			-- the repository is not broken, it just has some
+			-- unusual tree objects in it. So ignore nonzero
+			-- exit status.
+			AllDuplicateEntriesWarning -> return noproblem
+	go _ _ _ _ = error "internal"
+	
 	maxobjs = 10000
 	noproblem = FsckFoundMissing S.empty False
 
@@ -117,9 +121,9 @@ knownMissing (FsckFoundMissing s _) = s
 findMissing :: [Sha] -> Repo -> IO MissingObjects
 findMissing objs r = S.fromList <$> filterM (`isMissing` r) objs
 
-parseFsckOutput :: Int -> Repo -> Handle -> IO FsckOutput
-parseFsckOutput maxobjs r h = do
-	ls <- lines <$> hGetContents h
+parseFsckOutput :: Int -> Repo -> Handle -> ProcessHandle -> IO FsckOutput
+parseFsckOutput maxobjs r h pid = do
+	ls <- getlines []
 	if null ls
 		then return NoFsckOutput
 		else if all ("duplicateEntries" `isInfixOf`) ls
@@ -129,6 +133,10 @@ parseFsckOutput maxobjs r h = do
 				let !truncated = length shas > maxobjs
 				missingobjs <- findMissing (take maxobjs shas) r
 				return $ FsckOutput missingobjs truncated
+  where
+	getlines c = hGetLineUntilExitOrEOF pid h >>= \case
+		Nothing -> return (reverse c)
+		Just l -> getlines (l:c)
 
 isMissing :: Sha -> Repo -> IO Bool
 isMissing s r = either (const True) (const False) <$> tryIO dump
diff --git a/Git/HashObject.hs b/Git/HashObject.hs
index bcad9a1..98bd440 100644
--- a/Git/HashObject.hs
+++ b/Git/HashObject.hs
@@ -36,10 +36,10 @@ hashObjectStop :: HashObjectHandle -> IO ()
 hashObjectStop = CoProcess.stop
 
 {- Injects a file into git, returning the Sha of the object. -}
-hashFile :: HashObjectHandle -> FilePath -> IO Sha
+hashFile :: HashObjectHandle -> RawFilePath -> IO Sha
 hashFile h file = CoProcess.query h send receive
   where
-	send to = hPutStrLn to =<< absPath file
+	send to = S8.hPutStrLn to =<< absPath file
 	receive from = getSha "hash-object" $ S8.hGetLine from
 
 class HashableBlob t where
@@ -60,7 +60,7 @@ hashBlob :: HashableBlob b => HashObjectHandle -> b -> IO Sha
 hashBlob h b = withTmpFile "hash" $ \tmp tmph -> do
 	hashableBlobToHandle tmph b
 	hClose tmph
-	hashFile h tmp
+	hashFile h (toRawFilePath tmp)
 
 {- Injects some content into git, returning its Sha.
  - 
diff --git a/Git/Index.hs b/Git/Index.hs
index afd29c2..b55fc04 100644
--- a/Git/Index.hs
+++ b/Git/Index.hs
@@ -5,6 +5,8 @@
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
+{-# LANGUAGE OverloadedStrings #-}
+
 module Git.Index where
 
 import Common
@@ -12,6 +14,8 @@ import Git
 import Utility.Env
 import Utility.Env.Set
 
+import qualified System.FilePath.ByteString as P
+
 indexEnv :: String
 indexEnv = "GIT_INDEX_FILE"
 
@@ -26,8 +30,8 @@ indexEnv = "GIT_INDEX_FILE"
  -
  - So, an absolute path is the only safe option for this to return.
  -}
-indexEnvVal :: FilePath -> IO String
-indexEnvVal = absPath
+indexEnvVal :: RawFilePath -> IO String
+indexEnvVal p = fromRawFilePath <$> absPath p
 
 {- Forces git to use the specified index file.
  -
@@ -36,7 +40,7 @@ indexEnvVal = absPath
  -
  - Warning: Not thread safe.
  -}
-override :: FilePath -> Repo -> IO (IO ())
+override :: RawFilePath -> Repo -> IO (IO ())
 override index _r = do
 	res <- getEnv var
 	val <- indexEnvVal index
@@ -48,13 +52,13 @@ override index _r = do
 	reset _ = unsetEnv var
 
 {- The normal index file. Does not check GIT_INDEX_FILE. -}
-indexFile :: Repo -> FilePath
-indexFile r = fromRawFilePath (localGitDir r) </> "index"
+indexFile :: Repo -> RawFilePath
+indexFile r = localGitDir r P.</> "index"
 
 {- The index file git will currently use, checking GIT_INDEX_FILE. -}
-currentIndexFile :: Repo -> IO FilePath
-currentIndexFile r = fromMaybe (indexFile r) <$> getEnv indexEnv	
+currentIndexFile :: Repo -> IO RawFilePath
+currentIndexFile r = maybe (indexFile r) toRawFilePath <$> getEnv indexEnv
 
 {- Git locks the index by creating this file. -}
-indexFileLock :: FilePath -> FilePath
-indexFileLock f = f ++ ".lock"
+indexFileLock :: RawFilePath -> RawFilePath
+indexFileLock f = f <> ".lock"
diff --git a/Git/LsFiles.hs b/Git/LsFiles.hs
index 830b5f5..297c068 100644
--- a/Git/LsFiles.hs
+++ b/Git/LsFiles.hs
@@ -1,22 +1,24 @@
 {- git ls-files interface
  -
- - Copyright 2010-2019 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
 module Git.LsFiles (
+	Options(..),
 	inRepo,
+	inRepoDetails,
 	inRepoOrBranch,
 	notInRepo,
 	notInRepoIncludingEmptyDirectories,
 	allFiles,
 	deleted,
 	modified,
-	modifiedOthers,
 	staged,
 	stagedNotDeleted,
-	stagedOthersDetails,
+	usualStageNum,
+	mergeConflictHeadStageNum,
 	stagedDetails,
 	typeChanged,
 	typeChangedStaged,
@@ -34,12 +36,15 @@ import Git.Types
 import Git.Sha
 import Utility.InodeCache
 import Utility.TimeStamp
+import Utility.Attoparsec
+import qualified Utility.RawFilePath as R
 
-import Numeric
-import Data.Char
 import System.Posix.Types
 import qualified Data.Map as M
 import qualified Data.ByteString as S
+import qualified Data.Attoparsec.ByteString as A
+import qualified Data.Attoparsec.ByteString.Char8 as A8
+import qualified System.FilePath.ByteString as P
 
 {- It's only safe to use git ls-files on the current repo, not on a remote.
  -
@@ -63,101 +68,75 @@ guardSafeForLsFiles r a
 	| safeForLsFiles r = a
 	| otherwise = error $ "git ls-files is unsafe to run on repository " ++ repoDescribe r
 
+data Options = ErrorUnmatch
+
+opParam :: Options -> CommandParam
+opParam ErrorUnmatch = Param "--error-unmatch"
+
 {- Lists files that are checked into git's index at the specified paths.
  - With no paths, all files are listed.
  -}
-inRepo :: [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-inRepo = inRepo' [] 
+inRepo :: [Options] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+inRepo = inRepo' [Param "--cached"] 
 
-inRepo' :: [CommandParam] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-inRepo' ps l repo = guardSafeForLsFiles repo $ pipeNullSplit' params repo
+inRepo' :: [CommandParam] -> [Options] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+inRepo' ps os l repo = guardSafeForLsFiles repo $ pipeNullSplit' params repo
   where
 	params = 
 		Param "ls-files" :
-		Param "--cached" :
 		Param "-z" :
-		ps ++
+		map opParam os ++ ps ++
 		(Param "--" : map (File . fromRawFilePath) l)
 
+{- Lists the same files inRepo does, but with sha and mode. -}
+inRepoDetails :: [Options] -> [RawFilePath] -> Repo -> IO ([(RawFilePath, Sha, FileMode)], IO Bool)
+inRepoDetails = stagedDetails' parser . map opParam
+  where
+	parser s = case parseStagedDetails s of
+		Just (file, sha, mode, stagenum)
+			| stagenum == usualStageNum || stagenum == mergeConflictHeadStageNum ->
+				Just (file, sha, mode)
+		_ -> Nothing
+
 {- Files that are checked into the index or have been committed to a
  - branch. -}
-inRepoOrBranch :: Branch -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-inRepoOrBranch b = inRepo' [Param $ "--with-tree=" ++ fromRef b]
+inRepoOrBranch :: Branch -> [Options] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+inRepoOrBranch b = inRepo'
+	[ Param "--cached"
+	, Param ("--with-tree=" ++ fromRef b)
+	]
 
 {- Scans for files at the specified locations that are not checked into git. -}
-notInRepo :: Bool -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+notInRepo :: [Options] -> Bool -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
 notInRepo = notInRepo' []
 
-notInRepo' :: [CommandParam] -> Bool -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-notInRepo' ps include_ignored l repo = guardSafeForLsFiles repo $
-	pipeNullSplit' params repo
+notInRepo' :: [CommandParam] -> [Options] -> Bool -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+notInRepo' ps os include_ignored = 
+	inRepo' (Param "--others" : ps ++ exclude) os
   where
-	params = concat
-		[ [ Param "ls-files", Param "--others"]
-		, ps
-		, exclude
-		, [ Param "-z", Param "--" ]
-		, map (File . fromRawFilePath) l
-		]
 	exclude
 		| include_ignored = []
 		| otherwise = [Param "--exclude-standard"]
 
 {- Scans for files at the specified locations that are not checked into
  - git. Empty directories are included in the result. -}
-notInRepoIncludingEmptyDirectories :: Bool -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+notInRepoIncludingEmptyDirectories :: [Options] -> Bool -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
 notInRepoIncludingEmptyDirectories = notInRepo' [Param "--directory"]
 
 {- Finds all files in the specified locations, whether checked into git or
  - not. -}
-allFiles :: [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-allFiles l repo = guardSafeForLsFiles repo $ pipeNullSplit' params repo
-  where
-	params =
-		Param "ls-files" :
-		Param "--cached" :
-		Param "--others" :
-		Param "-z" :
-		Param "--" :
-		map (File . fromRawFilePath) l
+allFiles :: [Options] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+allFiles = inRepo' [Param "--cached", Param "--others"]
 
 {- Returns a list of files in the specified locations that have been
  - deleted. -}
-deleted :: [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-deleted l repo = guardSafeForLsFiles repo $ pipeNullSplit' params repo
-  where
-	params =
-		Param "ls-files" :
-		Param "--deleted" :
-		Param "-z" :
-		Param "--" :
-		map (File . fromRawFilePath) l
+deleted :: [Options] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+deleted = inRepo' [Param "--deleted"]
 
 {- Returns a list of files in the specified locations that have been
  - modified. -}
-modified :: [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-modified l repo = guardSafeForLsFiles repo $ pipeNullSplit' params repo
-  where
-	params = 
-		Param "ls-files" :
-		Param "--modified" :
-		Param "-z" :
-		Param "--" :
-		map (File . fromRawFilePath) l
-
-{- Files that have been modified or are not checked into git (and are not
- - ignored). -}
-modifiedOthers :: [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
-modifiedOthers l repo = guardSafeForLsFiles repo $ pipeNullSplit' params repo
-  where
-	params = 
-		Param "ls-files" :
-		Param "--modified" :
-		Param "--others" :
-		Param "--exclude-standard" :
-		Param "-z" :
-		Param "--" :
-		map (File . fromRawFilePath) l
+modified :: [Options] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
+modified = inRepo' [Param "--modified"]
 
 {- Returns a list of all files that are staged for commit. -}
 staged :: [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
@@ -175,36 +154,49 @@ staged' ps l repo = guardSafeForLsFiles repo $
 	prefix = [Param "diff", Param "--cached", Param "--name-only", Param "-z"]
 	suffix = Param "--" : map (File . fromRawFilePath) l
 
-type StagedDetails = (RawFilePath, Maybe Sha, Maybe FileMode)
+type StagedDetails = (RawFilePath, Sha, FileMode, StageNum)
+
+type StageNum = Int
 
-{- Returns details about files that are staged in the index,
- - as well as files not yet in git. Skips ignored files. -}
-stagedOthersDetails :: [RawFilePath] -> Repo -> IO ([StagedDetails], IO Bool)
-stagedOthersDetails = stagedDetails' [Param "--others", Param "--exclude-standard"]
+{- Used when not in a merge conflict. -}
+usualStageNum :: Int
+usualStageNum = 0
 
-{- Returns details about all files that are staged in the index. -}
+{- WHen in a merge conflict, git uses stage number 2 for the local HEAD
+ - side of the merge conflict. -}
+mergeConflictHeadStageNum :: Int
+mergeConflictHeadStageNum = 2
+
+{- Returns details about all files that are staged in the index.
+ -
+ - Note that, during a conflict, a file will appear in the list
+ - more than once with different stage numbers.
+ -}
 stagedDetails :: [RawFilePath] -> Repo -> IO ([StagedDetails], IO Bool)
-stagedDetails = stagedDetails' []
+stagedDetails = stagedDetails' parseStagedDetails []
 
-{- Gets details about staged files, including the Sha of their staged
- - contents. -}
-stagedDetails' :: [CommandParam] -> [RawFilePath] -> Repo -> IO ([StagedDetails], IO Bool)
-stagedDetails' ps l repo = guardSafeForLsFiles repo $ do
+stagedDetails' :: (S.ByteString -> Maybe t) -> [CommandParam] -> [RawFilePath] -> Repo -> IO ([t], IO Bool)
+stagedDetails' parser ps l repo = guardSafeForLsFiles repo $ do
 	(ls, cleanup) <- pipeNullSplit' params repo
-	return (map parseStagedDetails ls, cleanup)
+	return (mapMaybe parser ls, cleanup)
   where
 	params = Param "ls-files" : Param "--stage" : Param "-z" : ps ++ 
 		Param "--" : map (File . fromRawFilePath) l
 
-parseStagedDetails :: S.ByteString -> StagedDetails
-parseStagedDetails s
-	| S.null file = (s, Nothing, Nothing)
-	| otherwise = (file, extractSha sha, readmode mode)
+parseStagedDetails :: S.ByteString -> Maybe StagedDetails
+parseStagedDetails = eitherToMaybe . A.parseOnly parser
   where
-	(metadata, file) = separate' (== fromIntegral (ord '\t')) s
-	(mode, metadata') = separate' (== fromIntegral (ord ' ')) metadata
-	(sha, _) = separate' (== fromIntegral (ord ' ')) metadata'
-	readmode = fst <$$> headMaybe . readOct . decodeBS'
+	parser = do
+		mode <- octal
+		void $ A8.char ' '
+		sha <- maybe (fail "bad sha") return . extractSha =<< nextword
+		void $ A8.char ' '
+		stagenum <- A8.decimal
+		void $ A8.char '\t'
+		file <- A.takeByteString
+		return (file, sha, mode, stagenum)
+	
+	nextword = A8.takeTill (== ' ')
 
 {- Returns a list of the files in the specified locations that are staged
  - for commit, and whose type has changed. -}
@@ -218,12 +210,12 @@ typeChanged = typeChanged' []
 
 typeChanged' :: [CommandParam] -> [RawFilePath] -> Repo -> IO ([RawFilePath], IO Bool)
 typeChanged' ps l repo = guardSafeForLsFiles repo $ do
-	(fs, cleanup) <- pipeNullSplit (prefix ++ ps ++ suffix) repo
+	(fs, cleanup) <- pipeNullSplit' (prefix ++ ps ++ suffix) repo
 	-- git diff returns filenames relative to the top of the git repo;
 	-- convert to filenames relative to the cwd, like git ls-files.
-	top <- absPath (fromRawFilePath (repoPath repo))
-	currdir <- getCurrentDirectory
-	return (map (\f -> toRawFilePath (relPathDirToFileAbs currdir $ top </> decodeBL' f)) fs, cleanup)
+	top <- absPath (repoPath repo)
+	currdir <- R.getCurrentDirectory
+	return (map (\f -> relPathDirToFileAbs currdir $ top P.</> f) fs, cleanup)
   where
 	prefix = 
 		[ Param "diff"
diff --git a/Git/LsTree.hs b/Git/LsTree.hs
index ead501f..cd0d406 100644
--- a/Git/LsTree.hs
+++ b/Git/LsTree.hs
@@ -1,17 +1,17 @@
 {- git ls-tree interface
  -
- - Copyright 2011-2019 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
-{-# LANGUAGE BangPatterns #-}
-
 module Git.LsTree (
 	TreeItem(..),
 	LsTreeMode(..),
 	lsTree,
 	lsTree',
+	lsTreeStrict,
+	lsTreeStrict',
 	lsTreeParams,
 	lsTreeFiles,
 	parseLsTree,
@@ -30,6 +30,7 @@ import Data.Either
 import System.Posix.Types
 import qualified Data.ByteString as S
 import qualified Data.ByteString.Lazy as L
+import qualified Data.Attoparsec.ByteString as AS
 import qualified Data.Attoparsec.ByteString.Lazy as A
 import qualified Data.Attoparsec.ByteString.Char8 as A8
 
@@ -38,7 +39,7 @@ data TreeItem = TreeItem
 	, typeobj :: S.ByteString
 	, sha :: Ref
 	, file :: TopFilePath
-	} deriving Show
+	} deriving (Show)
 
 data LsTreeMode = LsTreeRecursive | LsTreeNonRecursive
 
@@ -51,6 +52,13 @@ lsTree' ps lsmode t repo = do
 	(l, cleanup) <- pipeNullSplit (lsTreeParams lsmode t ps) repo
 	return (rights (map parseLsTree l), cleanup)
 
+lsTreeStrict :: LsTreeMode -> Ref -> Repo -> IO [TreeItem]
+lsTreeStrict = lsTreeStrict' []
+
+lsTreeStrict' :: [CommandParam] -> LsTreeMode -> Ref -> Repo -> IO [TreeItem]
+lsTreeStrict' ps lsmode t repo = rights . map parseLsTreeStrict
+	<$> pipeNullSplitStrict (lsTreeParams lsmode t ps) repo
+
 lsTreeParams :: LsTreeMode -> Ref -> [CommandParam] -> [CommandParam]
 lsTreeParams lsmode r ps =
 	[ Param "ls-tree"
@@ -83,6 +91,13 @@ parseLsTree b = case A.parse parserLsTree b of
 	A.Done _ r  -> Right r
 	A.Fail _ _ err -> Left err
 
+parseLsTreeStrict :: S.ByteString -> Either String TreeItem
+parseLsTreeStrict b = go (AS.parse parserLsTree b)
+  where
+	go (AS.Done _ r) = Right r
+	go (AS.Fail _ _ err) = Left err
+	go (AS.Partial c) = go (c mempty)
+
 {- Parses a line of ls-tree output, in format:
  - mode SP type SP sha TAB file
  -
diff --git a/Git/Objects.hs b/Git/Objects.hs
index 6a24087..9b7165c 100644
--- a/Git/Objects.hs
+++ b/Git/Objects.hs
@@ -5,39 +5,45 @@
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
+{-# LANGUAGE OverloadedStrings #-}
+
 module Git.Objects where
 
 import Common
 import Git
 import Git.Sha
 
-objectsDir :: Repo -> FilePath
-objectsDir r = fromRawFilePath (localGitDir r) </> "objects"
+import qualified Data.ByteString as B
+import qualified System.FilePath.ByteString as P
+
+objectsDir :: Repo -> RawFilePath
+objectsDir r = localGitDir r P.</> "objects"
 
-packDir :: Repo -> FilePath
-packDir r = objectsDir r </> "pack"
+packDir :: Repo -> RawFilePath
+packDir r = objectsDir r P.</> "pack"
 
-packIdxFile :: FilePath -> FilePath
-packIdxFile = flip replaceExtension "idx"
+packIdxFile :: RawFilePath -> RawFilePath
+packIdxFile = flip P.replaceExtension "idx"
 
 listPackFiles :: Repo -> IO [FilePath]
 listPackFiles r = filter (".pack" `isSuffixOf`) 
-	<$> catchDefaultIO [] (dirContents $ packDir r)
+	<$> catchDefaultIO [] (dirContents $ fromRawFilePath $ packDir r)
 
 listLooseObjectShas :: Repo -> IO [Sha]
 listLooseObjectShas r = catchDefaultIO [] $
 	mapMaybe (extractSha . encodeBS . concat . reverse . take 2 . reverse . splitDirectories)
-		<$> dirContentsRecursiveSkipping (== "pack") True (objectsDir r)
+		<$> dirContentsRecursiveSkipping (== "pack") True (fromRawFilePath (objectsDir r))
 
-looseObjectFile :: Repo -> Sha -> FilePath
-looseObjectFile r sha = objectsDir r </> prefix </> rest
+looseObjectFile :: Repo -> Sha -> RawFilePath
+looseObjectFile r sha = objectsDir r P.</> prefix P.</> rest
   where
-	(prefix, rest) = splitAt 2 (fromRef sha)
+	(prefix, rest) = B.splitAt 2 (fromRef' sha)
 
 listAlternates :: Repo -> IO [FilePath]
-listAlternates r = catchDefaultIO [] (lines <$> readFile alternatesfile)
+listAlternates r = catchDefaultIO [] $
+	lines <$> readFile (fromRawFilePath alternatesfile)
   where
-	alternatesfile = objectsDir r </> "info" </> "alternates"
+	alternatesfile = objectsDir r P.</> "info" P.</> "alternates"
 
 {- A repository recently cloned with --shared will have one or more
  - alternates listed, and contain no loose objects or packs. -}
diff --git a/Git/Ref.hs b/Git/Ref.hs
index 104a1db..7179a4e 100644
--- a/Git/Ref.hs
+++ b/Git/Ref.hs
@@ -1,6 +1,6 @@
 {- git ref stuff
  -
- - Copyright 2011-2019 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -14,6 +14,7 @@ import Git
 import Git.Command
 import Git.Sha
 import Git.Types
+import Git.FilePath
 
 import Data.Char (chr, ord)
 import qualified Data.ByteString as S
@@ -68,7 +69,11 @@ branchRef = underBase "refs/heads"
  - of a repo.
  -}
 fileRef :: RawFilePath -> Ref
-fileRef f = Ref $ ":./" <> f
+fileRef f = Ref $ ":./" <> toInternalGitPath f
+
+{- A Ref that can be used to refer to a file in a particular branch. -}
+branchFileRef :: Branch -> RawFilePath -> Ref
+branchFileRef branch f = Ref $ fromRef' branch <> ":" <> toInternalGitPath f
 
 {- Converts a Ref to refer to the content of the Ref on a given date. -}
 dateRef :: Ref -> RefDate -> Ref
diff --git a/Git/Repair.hs b/Git/Repair.hs
index f81aa78..ea682a2 100644
--- a/Git/Repair.hs
+++ b/Git/Repair.hs
@@ -5,6 +5,8 @@
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
+{-# LANGUAGE OverloadedStrings #-}
+
 module Git.Repair (
 	runRepair,
 	runRepairOf,
@@ -35,13 +37,15 @@ import qualified Git.Ref as Ref
 import qualified Git.RefLog as RefLog
 import qualified Git.UpdateIndex as UpdateIndex
 import qualified Git.Branch as Branch
+import Utility.Directory.Create
 import Utility.Tmp.Dir
 import Utility.Rsync
 import Utility.FileMode
-import Utility.Tuple
+import qualified Utility.RawFilePath as R
 
 import qualified Data.Set as S
 import qualified Data.ByteString.Lazy as L
+import qualified System.FilePath.ByteString as P
 
 {- Given a set of bad objects found by git fsck, which may not
  - be complete, finds and removes all corrupt objects. -}
@@ -51,9 +55,9 @@ cleanCorruptObjects fsckresults r = do
 	mapM_ removeLoose (S.toList $ knownMissing fsckresults)
 	mapM_ removeBad =<< listLooseObjectShas r
   where
-	removeLoose s = nukeFile (looseObjectFile r s)
+	removeLoose s = removeWhenExistsWith R.removeLink (looseObjectFile r s)
 	removeBad s = do
-		void $ tryIO $ allowRead $  looseObjectFile r s
+		void $ tryIO $ allowRead $ looseObjectFile r s
 		whenM (isMissing s r) $
 			removeLoose s
 
@@ -77,10 +81,11 @@ explodePacks r = go =<< listPackFiles r
 		putStrLn "Unpacking all pack files."
 		forM_ packs $ \packfile -> do
 			moveFile packfile (tmpdir </> takeFileName packfile)
-			nukeFile $ packIdxFile packfile
+			removeWhenExistsWith R.removeLink
+				(packIdxFile (toRawFilePath packfile))
 		forM_ packs $ \packfile -> do
 			let tmp = tmpdir </> takeFileName packfile
-			allowRead tmp
+			allowRead (toRawFilePath tmp)
 			-- May fail, if pack file is corrupt.
 			void $ tryIO $
 				pipeWrite [Param "unpack-objects", Param "-r"] r $ \h ->
@@ -100,7 +105,7 @@ retrieveMissingObjects missing referencerepo r
 	| otherwise = withTmpDir "tmprepo" $ \tmpdir -> do
 		unlessM (boolSystem "git" [Param "init", File tmpdir]) $
 			error $ "failed to create temp repository in " ++ tmpdir
-		tmpr <- Config.read =<< Construct.fromAbsPath tmpdir
+		tmpr <- Config.read =<< Construct.fromAbsPath (toRawFilePath tmpdir)
 		rs <- Construct.fromRemotes r
 		stillmissing <- pullremotes tmpr rs fetchrefstags missing
 		if S.null (knownMissing stillmissing)
@@ -161,8 +166,8 @@ retrieveMissingObjects missing referencerepo r
 copyObjects :: Repo -> Repo -> IO Bool
 copyObjects srcr destr = rsync
 	[ Param "-qr"
-	, File $ addTrailingPathSeparator $ objectsDir srcr
-	, File $ addTrailingPathSeparator $ objectsDir destr
+	, File $ addTrailingPathSeparator $ fromRawFilePath $ objectsDir srcr
+	, File $ addTrailingPathSeparator $ fromRawFilePath $ objectsDir destr
 	]
 
 {- To deal with missing objects that cannot be recovered, resets any
@@ -240,18 +245,20 @@ getAllRefs' refdir = do
 explodePackedRefsFile :: Repo -> IO ()
 explodePackedRefsFile r = do
 	let f = packedRefsFile r
+	let f' = toRawFilePath f
 	whenM (doesFileExist f) $ do
 		rs <- mapMaybe parsePacked . lines
-			<$> catchDefaultIO "" (safeReadFile f)
+			<$> catchDefaultIO "" (safeReadFile f')
 		forM_ rs makeref
-		nukeFile f
+		removeWhenExistsWith R.removeLink f'
   where
 	makeref (sha, ref) = do
-		let gitd = fromRawFilePath (localGitDir r)
-		let dest = gitd </> fromRef ref
+		let gitd = localGitDir r
+		let dest = gitd P.</> fromRef' ref
+		let dest' = fromRawFilePath dest
 		createDirectoryUnder gitd (parentDir dest)
-		unlessM (doesFileExist dest) $
-			writeFile dest (fromRef sha)
+		unlessM (doesFileExist dest') $
+			writeFile dest' (fromRef sha)
 
 packedRefsFile :: Repo -> FilePath
 packedRefsFile r = fromRawFilePath (localGitDir r) </> "packed-refs"
@@ -266,7 +273,7 @@ parsePacked l = case words l of
 {- git-branch -d cannot be used to remove a branch that is directly
  - pointing to a corrupt commit. -}
 nukeBranchRef :: Branch -> Repo -> IO ()
-nukeBranchRef b r = nukeFile $ fromRawFilePath (localGitDir r) </> fromRef b
+nukeBranchRef b r = removeWhenExistsWith R.removeLink $ localGitDir r P.</> fromRef' b
 
 {- Finds the most recent commit to a branch that does not need any
  - of the missing objects. If the input branch is good as-is, returns it.
@@ -379,9 +386,8 @@ missingIndex r = not <$> doesFileExist (fromRawFilePath (localGitDir r) </> "ind
 partitionIndex :: Repo -> IO ([LsFiles.StagedDetails], [LsFiles.StagedDetails], IO Bool)
 partitionIndex r = do
 	(indexcontents, cleanup) <- LsFiles.stagedDetails [repoPath r] r
-	l <- forM indexcontents $ \i -> case i of
-		(_file, Just sha, Just _mode) -> (,) <$> isMissing sha r <*> pure i
-		_ -> pure (False, i)
+	l <- forM indexcontents $ \i@(_file, sha, _mode, _stagenum) -> 
+		(,) <$> isMissing sha r <*> pure i
 	let (bad, good) = partition fst l
 	return (map snd bad, map snd good, cleanup)
 
@@ -393,17 +399,16 @@ rewriteIndex r
 	| otherwise = do
 		(bad, good, cleanup) <- partitionIndex r
 		unless (null bad) $ do
-			nukeFile (indexFile r)
+			removeWhenExistsWith R.removeLink (indexFile r)
 			UpdateIndex.streamUpdateIndex r
 				=<< (catMaybes <$> mapM reinject good)
 		void cleanup
-		return $ map (fromRawFilePath . fst3) bad
+		return $ map (\(file,_, _, _) -> fromRawFilePath file) bad
   where
-	reinject (file, Just sha, Just mode) = case toTreeItemType mode of
+	reinject (file, sha, mode, _) = case toTreeItemType mode of
 		Nothing -> return Nothing
 		Just treeitemtype -> Just <$>
 			UpdateIndex.stageFile sha treeitemtype (fromRawFilePath file) r
-	reinject _ = return Nothing
 
 newtype GoodCommits = GoodCommits (S.Set Sha)
 
@@ -442,14 +447,13 @@ displayList items header
 preRepair :: Repo -> IO ()
 preRepair g = do
 	unlessM (validhead <$> catchDefaultIO "" (safeReadFile headfile)) $ do
-		nukeFile headfile
-		writeFile headfile "ref: refs/heads/master"
+		removeWhenExistsWith R.removeLink headfile
+		writeFile (fromRawFilePath headfile) "ref: refs/heads/master"
 	explodePackedRefsFile g
-	unless (repoIsLocalBare g) $ do
-		let f = indexFile g
-		void $ tryIO $ allowWrite f
+	unless (repoIsLocalBare g) $
+		void $ tryIO $ allowWrite $ indexFile g
   where
-	headfile = fromRawFilePath (localGitDir g) </> "HEAD"
+	headfile = localGitDir g P.</> "HEAD"
 	validhead s = "ref: refs/" `isPrefixOf` s
 		|| isJust (extractSha (encodeBS' s))
 
@@ -571,7 +575,7 @@ runRepair' removablebranch fsckresult forced referencerepo g = do
 			else successfulfinish modifiedbranches
 
 	corruptedindex = do
-		nukeFile (indexFile g)
+		removeWhenExistsWith R.removeLink (indexFile g)
 		-- The corrupted index can prevent fsck from finding other
 		-- problems, so re-run repair.
 		fsckresult' <- findBroken False g
@@ -615,7 +619,7 @@ runRepair' removablebranch fsckresult forced referencerepo g = do
 successfulRepair :: (Bool, [Branch]) -> Bool
 successfulRepair = fst
 
-safeReadFile :: FilePath -> IO String
+safeReadFile :: RawFilePath -> IO String
 safeReadFile f = do
 	allowRead f
-	readFileStrict f
+	readFileStrict (fromRawFilePath f)
diff --git a/Git/Types.hs b/Git/Types.hs
index 4bf61e5..73c4fe6 100644
--- a/Git/Types.hs
+++ b/Git/Types.hs
@@ -5,7 +5,7 @@
  - Licensed under the GNU AGPL version 3 or higher.
  -}
 
-{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE OverloadedStrings, TypeSynonymInstances, FlexibleInstances #-}
 
 module Git.Types where
 
@@ -79,9 +79,15 @@ fromConfigKey (ConfigKey s) = decodeBS' s
 instance Show ConfigKey where
 	show = fromConfigKey
 
-fromConfigValue :: ConfigValue -> String
-fromConfigValue (ConfigValue s) = decodeBS' s
-fromConfigValue NoConfigValue = mempty
+class FromConfigValue a where
+	fromConfigValue :: ConfigValue -> a
+
+instance FromConfigValue S.ByteString where
+	fromConfigValue (ConfigValue s) = s
+	fromConfigValue NoConfigValue = mempty
+
+instance FromConfigValue String where
+	fromConfigValue = decodeBS' . fromConfigValue
 
 instance Show ConfigValue where
 	show = fromConfigValue
@@ -129,7 +135,12 @@ fmtObjectType CommitObject = "commit"
 fmtObjectType TreeObject = "tree"
 
 {- Types of items in a tree. -}
-data TreeItemType = TreeFile | TreeExecutable | TreeSymlink | TreeSubmodule
+data TreeItemType
+	= TreeFile
+	| TreeExecutable
+	| TreeSymlink
+	| TreeSubmodule
+	| TreeSubtree
 	deriving (Eq, Show)
 
 {- Git uses magic numbers to denote the type of a tree item. -}
@@ -138,6 +149,7 @@ readTreeItemType "100644" = Just TreeFile
 readTreeItemType "100755" = Just TreeExecutable
 readTreeItemType "120000" = Just TreeSymlink
 readTreeItemType "160000" = Just TreeSubmodule
+readTreeItemType "040000" = Just TreeSubtree
 readTreeItemType _ = Nothing
 
 fmtTreeItemType :: TreeItemType -> S.ByteString
@@ -145,12 +157,14 @@ fmtTreeItemType TreeFile = "100644"
 fmtTreeItemType TreeExecutable = "100755"
 fmtTreeItemType TreeSymlink = "120000"
 fmtTreeItemType TreeSubmodule = "160000"
+fmtTreeItemType TreeSubtree = "040000"
 
 toTreeItemType :: FileMode -> Maybe TreeItemType
 toTreeItemType 0o100644 = Just TreeFile
 toTreeItemType 0o100755 = Just TreeExecutable
 toTreeItemType 0o120000 = Just TreeSymlink
 toTreeItemType 0o160000 = Just TreeSubmodule
+toTreeItemType 0o040000 = Just TreeSubtree
 toTreeItemType _ = Nothing
 
 fromTreeItemType :: TreeItemType -> FileMode
@@ -158,6 +172,7 @@ fromTreeItemType TreeFile = 0o100644
 fromTreeItemType TreeExecutable = 0o100755
 fromTreeItemType TreeSymlink = 0o120000
 fromTreeItemType TreeSubmodule = 0o160000
+fromTreeItemType TreeSubtree = 0o040000
 
 data Commit = Commit
 	{ commitTree :: Sha
diff --git a/Git/UpdateIndex.hs b/Git/UpdateIndex.hs
index f0331d5..8e406b1 100644
--- a/Git/UpdateIndex.hs
+++ b/Git/UpdateIndex.hs
@@ -1,6 +1,6 @@
 {- git-update-index library
  -
- - Copyright 2011-2019 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -12,8 +12,7 @@ module Git.UpdateIndex (
 	pureStreamer,
 	streamUpdateIndex,
 	streamUpdateIndex',
-	startUpdateIndex,
-	stopUpdateIndex,
+	withUpdateIndex,
 	lsTree,
 	lsSubTree,
 	updateIndexLine,
@@ -32,7 +31,9 @@ import Git.FilePath
 import Git.Sha
 import qualified Git.DiffTreeItem as Diff
 
+import qualified Data.ByteString as S
 import qualified Data.ByteString.Lazy as L
+import Control.Monad.IO.Class
 
 {- Streamers are passed a callback and should feed it lines in the form
  - read by update-index, and generated by ls-tree. -}
@@ -44,28 +45,32 @@ pureStreamer !s = \streamer -> streamer s
 
 {- Streams content into update-index from a list of Streamers. -}
 streamUpdateIndex :: Repo -> [Streamer] -> IO ()
-streamUpdateIndex repo as = bracket (startUpdateIndex repo) stopUpdateIndex $
-	(\h -> forM_ as $ streamUpdateIndex' h)
+streamUpdateIndex repo as = withUpdateIndex repo $ \h ->
+	forM_ as $ streamUpdateIndex' h
 
-data UpdateIndexHandle = UpdateIndexHandle ProcessHandle Handle
+data UpdateIndexHandle = UpdateIndexHandle Handle
 
 streamUpdateIndex' :: UpdateIndexHandle -> Streamer -> IO ()
-streamUpdateIndex' (UpdateIndexHandle _ h) a = a $ \s -> do
+streamUpdateIndex' (UpdateIndexHandle h) a = a $ \s -> do
 	L.hPutStr h s
 	L.hPutStr h "\0"
 
-startUpdateIndex :: Repo -> IO UpdateIndexHandle
-startUpdateIndex repo = do
-	(Just h, _, _, p) <- createProcess (gitCreateProcess params repo)
-		{ std_in = CreatePipe }
-	return $ UpdateIndexHandle p h
+withUpdateIndex :: (MonadIO m, MonadMask m) => Repo -> (UpdateIndexHandle -> m a) -> m a
+withUpdateIndex repo a = bracket setup cleanup go
   where
 	params = map Param ["update-index", "-z", "--index-info"]
-
-stopUpdateIndex :: UpdateIndexHandle -> IO Bool
-stopUpdateIndex (UpdateIndexHandle p h) = do
-	hClose h
-	checkSuccessProcess p
+	
+	setup = liftIO $ createProcess $ 
+		(gitCreateProcess params repo)
+			{ std_in = CreatePipe }
+	go p = do
+		r <- a (UpdateIndexHandle (stdinHandle p))
+		liftIO $ do
+			hClose (stdinHandle p)
+			void $ checkSuccessProcess (processHandle p)
+		return r
+	
+	cleanup = liftIO . cleanupProcess
 
 {- A streamer that adds the current tree for a ref. Useful for eg, copying
  - and modifying branches. -}
@@ -113,12 +118,12 @@ unstageFile' p = pureStreamer $ L.fromStrict $
 	<> indexPath p
 
 {- A streamer that adds a symlink to the index. -}
-stageSymlink :: FilePath -> Sha -> Repo -> IO Streamer
+stageSymlink :: RawFilePath -> Sha -> Repo -> IO Streamer
 stageSymlink file sha repo = do
 	!line <- updateIndexLine
 		<$> pure sha
 		<*> pure TreeSymlink
-		<*> toTopFilePath (toRawFilePath file) repo
+		<*> toTopFilePath file repo
 	return $ pureStreamer line
 
 {- A streamer that applies a DiffTreeItem to the index. -}
@@ -131,16 +136,8 @@ indexPath :: TopFilePath -> InternalGitPath
 indexPath = toInternalGitPath . getTopFilePath
 
 {- Refreshes the index, by checking file stat information.  -}
-refreshIndex :: Repo -> ((FilePath -> IO ()) -> IO ()) -> IO Bool
-refreshIndex repo feeder = do
-	(Just h, _, _, p) <- createProcess (gitCreateProcess params repo)
-		{ std_in = CreatePipe }
-	feeder $ \f -> do
-		hPutStr h f
-		hPutStr h "\0"
-	hFlush h
-	hClose h
-	checkSuccessProcess p
+refreshIndex :: Repo -> ((RawFilePath -> IO ()) -> IO ()) -> IO Bool
+refreshIndex repo feeder = withCreateProcess p go
   where
 	params = 
 		[ Param "update-index"
@@ -149,3 +146,14 @@ refreshIndex repo feeder = do
 		, Param "-z"
 		, Param "--stdin"
 		]
+	
+	p = (gitCreateProcess params repo)
+		{ std_in = CreatePipe }
+
+	go (Just h) _ _ pid = do
+		feeder $ \f ->
+			S.hPut h (S.snoc f 0)
+		hFlush h
+		hClose h
+		checkSuccessProcess pid
+	go _ _ _ _ = error "internal"
diff --git a/Git/Version.hs b/Git/Version.hs
index 5ecaca0..9119f5d 100644
--- a/Git/Version.hs
+++ b/Git/Version.hs
@@ -14,7 +14,7 @@ module Git.Version (
 	GitVersion,
 ) where
 
-import Common
+import Utility.Process
 import Utility.DottedVersion
 
 type GitVersion = DottedVersion